Health Effects Associated with Indoor Marijuana Grow ...

[Pages:26]Health Effects Associated with Indoor Marijuana Grow Operations

By

John W. Martyny, PhD Mike V. Van Dyke, PhD, CIH, CSP

Josh Schaeffer, M.S. Kate Serrano, MPH

Division of Environmental and Occupational Health Sciences Department of Medicine National Jewish Health Denver, CO

Introduction:

During the 1970's, most marijuana was grown in outdoor areas that were hard to find and were not readily visible to law enforcement. However, with new law enforcement techniques, including aircraft for surveillance, these large outdoor operations have become more vulnerable to detection and in much of the country growth is seasonally limited by temperature and light. In addition, restricting the pollination of the female plants in the outdoors is more difficult thereby limiting the 8-9-tetrahydrocannabinol (THC) content of the buds. These factors have contributed to an increase in indoor marijuana grow operations.

Indoor marijuana grow operations (MGO's) enable a year-long growing season in which conditions can be tightly controlled, resulting in plants with higher THC content per plant. A number of environmental factors must be monitored and kept in balance including the amount of light, the day-night periodicity, the carbon dioxide level, the humidity level and the temperature. In addition, the plants must be provided with adequate nutrition and pests must be kept under control.

Although these production factors could be provided in a greenhouse, such a growth area is very likely to be spotted by law enforcement officials or individuals wishing to steal the crop. In order to prevent detection, MGO's are frequently established in a house or a portion of a house that can be easily confined. Since a residential structure is not designed to function as a greenhouse, contamination by pesticides and fertilizers is more difficult to control, moisture can cause damage to building materials and result in excessive mold growth, and the risk of fire is significantly increased.

In order to provide the best growth environment for marijuana, temperature and humidity must be regulated. Temperature is normally kept between 21 degrees C. and 32 degrees C. (although some references indicate that the optimum temperature may be as high as 35 degrees C). The relative humidity is normally kept between 50% and 70% according to most sources although there have been some reports of relative humidity exceeding 90%. Typically, the relative humidity is dependent upon the amount of ventilation that can be provided and not the humidity that the plant needs. The allowable ventilation is likely determined by the need for secrecy, which may result in relatively high levels of humidity. The elevated relative humidity coupled with the elevated temperatures and the need for irrigation, frequently enables fungal growth within the structure. Increased fungal growth within the structure results in elevated mold exposures, of special concern when children are involved, as well as the possibility of actual structural damage to the residence.

Airborne levels of mold spores within these structures may subject the occupants, emergency personnel and other individuals to significant health hazards. Persons residing in these homes are likely to have levels of exposure that can cause hypersensitivity pneumonitis, allergic rhinitis, asthma, and other respiratory diseases. Emergency personnel and law enforcement officers entering these facilities on a regular basis have reported upper respiratory irritation, skin rashes, and other symptoms

associated with these exposures. Officers with pre-existing conditions such as asthma have reported an exacerbation of their existing conditions while dismantling indoor MGO's.

A factor that is very important in determining the THC content of plants is an elevated carbon dioxide level. The normal carbon dioxide level in the outside air ranges from 300 ppm to 400 ppm. In MGO's it is desirable to have levels of carbon dioxide that exceed 700 ppm with 2000 ppm being the highest desirable level. Most marijuana operations attempt to keep carbon dioxide levels at between 700 ppm and 1500 ppm. While these levels of carbon dioxide are not of public health concern, they do cause to ancillary problems. First, in order to keep carbon dioxide levels high, ventilation rates normally need to be reduced often leading to excess moisture. Secondly, if the carbon dioxide is generated by the use of fossil fuel combustion, carbon monoxide and oxides of nitrogen can be produced. Both of these compounds can be very dangerous and cause significant health effects in exposed individuals.

Chemicals are also utilized as fertilizers and pesticides. Although these chemicals may not usually cause a high degree of concern when used by qualified individuals, the use by individuals unaware of the dangers may result in risk to the neighborhood, children involved with the residence, and anyone unknowingly residing in the residence after its use as an MGO.

Exposure to the fore-mentioned hazards may result in a community public health concern. Although the greatest risk is borne by the individuals residing in the residence, others may also be impacted. MGO's located in multi-family buildings may allow the distribution of the chemicals used and/or produced into the ventilation system creating an exposure situation in other residences. Exposures to children living in these operations also present a public health hazard since the exposures may result in injury or death to an innocent child. Fires and explosions may cause damage to not only the MGO but also to surrounding houses. Lastly, these operations may go undetected putting an unsuspecting family buying the residence at a later date at risk of adverse health effects.

This project was designed to quantify the chemical and biological exposures associated with MGO's in Colorado and, from this information, to determine the procedures and personal protective equipment necessary for entry into indoor marijuana grow operations.

Methodology:

As noted above, there are a number of concerns associated with MGO's. Concerns include chemical contamination, carbon monoxide and other combustion products, as well as excessive fungal contamination due to the high humidity in the home. Some MGO's have carbon dioxide generators that utilize fossil fuel combustion potentially resulting in the production of carbon monoxide and nitrogen oxides. Fungal and bacterial growth may also be of great concern due to the high humidity and presence of organic materials in the house. We were also interested in the amount of THC present in the air and on surfaces within these MGO's.

Based on these concerns, we conducted an extensive sampling effort in 30 MGO operations. These operations were identified by law enforcement and were sampled shortly after the entry of law enforcement personnel.

The first step was to survey the facility to determine the chemicals utilized, including any pesticides, fertilizers, etc. Real-time levels of carbon monoxide, carbon dioxide, temperature, and relative humidity within the MGO were collected using portable, datarecording equipment. Gas Chromatograph/Mass Spectrometer samples for organics using EPA Method TO-17 were collected for analysis at a commercial laboratory. Airborne THC levels were collected using a fiberglass filter and surface THC levels were collected using a cotton swipe.

After beginning the collection for chemical contaminants, we began sampling for bioaerosols. Bioaerosol samples were collected using an N-6 Cascade Impactor and spore traps. Using the N-6, viable fungal samples were collected using malt extract and DG-18 plates at each location. A total of 4 plates were taken for 2 minutes at each location (2 malt extract and 2 DGA-18). Two spore traps were also taken at each location for a period of 10 minutes at a calibrated flow rate of 15 liters per minute. In addition, filter samples and settled dust samples were collected for analysis using quantitative polymerase chain reaction (QPCR).

The value of each of these mold sampling techniques was as follows:

Viable Samples ? These samples were collected using an Anderson Cascade Impactor to sample a known amount of air onto an agar plate. Two types of plates were utilized, malt extract plates for general molds and DG-18 plates for Stachybotris sp. This sampling technique allowed us to determine the types and amounts of molds present down to the species level.

Non-Viable Samples ? These samples were collected using a spore trap that collects the spores present in a known amount of air and allows them to be identified, generally to genus. The advantage to this type of sampling was that the organisms did not have to be grown and therefore some species were more easily identified. In addition, the actual number of mold spores present was more accurate since the spores are counted without the necessity of a growth phase.

PCR Samples ? These samples were collected on a filter that was then tested using polymerase chain reaction which is able to identify a number of species that may be present by looking for the rNA associated with that mold. This test is very specific for certain molds.

Dust Samples ? Samples of dust in the home were taken and analyzed using PCR technology again. The PCR is used to confirm the presence of specific molds that are associated with indoor mold growth and compare them with outside mold

species. This information was compared to an EPA database to determine the relative moldiness of the house.

As dismantling of the grow operation was expected increase exposures to law enforcement personnel, we also monitored any removal operation using the same methodologies outlined above.

Results:

Indoor MGO's Sampled

We responded and sampled a total of 24 indoor MGO's. The first MGO was a 4-plex that was essentially 4 MGO's in one and the 14th MGO was a large office building with 4 large grow rooms. The data provided will therefore contain information on a total of 30 MGO's.

Viable Mold Levels

In order to determine if mold spore levels are increased within a structure, we analyze several parameters. The first parameter that we examine is to determine if the total number of spores in the outside air is equal to the total number of spores observed within the structure. Since mold samples are grab samples and have a large distribution, we expect mold levels in problem houses to be 10 times higher than outside mold spore levels. An increase of 5 times may suggest that the structure has an elevated mold problem and that further data needs to be collected. In addition, we expect the species inside the house to be similar in abundance and species to the species and abundance outside. The rule of 10 times higher and 5 times higher again prevails.

Table #1 shows the relationship between the outside mold spore levels and the mold spore levels found in the different MGO's. The table provides the average mold spore levels observed in the outside air and the average mold spore levels found in the inside air. It also provides the range of mold spore levels found in each of those situations. In 5 of the MGO's sampled, the average mold spore level within the grow room was at least 10 times the average spore level in the outside air. This indicates that in those MGO's, the grow rooms were likely growing mold and may present a significant danger to individuals present within those rooms. An additional 3 MGO's had ranges where the highest range was elevated more than 10 times the levels found in the outside air again indicating that mold was growing in the structure. Table #1 also illustrates that in an additional 9 MGO's, the average level of spores was at least 5 times the outside levels suggesting that indoor mold growth was likely. Many of these samples contain results where the levels were as high as the method utilized could detect, indicating that the actual levels of mold were likely much higher.

The ranges have also been highlighted to show MGO's where the highest range within the grow room is at least 5 times the outside (yellow) or 10 times the outside levels (red).

Table #1

Plant Number

Total Outside

Grow Rooms

average range

average

range

1A

117 324 144-414

1048 522-1620

1B

77 324 144-414

1C

58 324 144-414

1745 1190-2300 662 486-1080

1D

28 324 144-414

1968 1640-2270

2

160 945 540-1256

2247 594-5330

3

65 464 360-738

4

670 189 144-270

>1366 396->5868 1085 612-1742

5

232 468 342-594

>6610 1746->11286

6

52 738 486-1044

3880 1638-9794

7

37 671 324-1134

8

24 671 324-1134

950 900-1080 752 576-918

9

86 671 324-1134

423 234-594

10

28 851 648-1116

911 504-1688

11

30 575 238-1026

12

11 1142 360-1886

386 323-468 360 306-450

13

290 554 342-756

441 216-918

14A

446 140 90-180

95 72-144

14B

323 140 90-180

>2862 252->5472

14C

107 140 90-180

>1544 144->5490

14D

84 140 90-180

>2840 198->5490

15

56 518 342-648

146 108-234

16

126 90-162

871 144-1724

17

188 401 252-594

>3150 144->5922

18

75 414 198-684

628 72-1134

19 20 100+

64 824 504-1188 3086.5* 2182-4028*

>3189 288->6430 >3613 1422->10836

21

240 438 252-756

>6422 >5976->6894

22

236 869 576-1242

>3582 846->6264

23

84 293 72-468

24

168 1993 180-3740

914 630-1188 >6728 >5436->8404

* - This outside level appears to be contaminated with inside mold

> - Greater than

These data indicate that the number of MGO's with elevated spore levels appear greatest when the number of plants exceeds 50. There are, however, some MGO's with larger numbers of plants that did not indicate elevated mold spore levels. Sample #20 includes an outside air sample that was taken on the steps of the MGO and was likely contaminated with indoor mold since the primary species (P. brevicompactum) was the main fungal contaminate inside and is not routinely found in high numbers on outside samples.

In some structures, the total mold spore counts were relatively similar between indoors and outdoors but the species of mold spores present was radically changed. We therefore looked not only at total mold spore levels but also mold species that were occurring within the MGO at levels exceeding outside levels. We found that Penicillium species typically occurred within the MGO's at much higher concentrations than are present in the outside air. Table #2 illustrates this difference.

Table #2

Pen. Outside

Grow Rooms

Grow Plant Number Average Range

Average Range

1A

117

14 0-36

18 0-36

1B

77

14 0-36

707 306-1116

1C

58

14 0-36

77 0-126

1D

28

14 0-36

23 0-36

2

160

14 0-54

155 0 - 558

3

65

14 0-54

56 0-198

4

670

36 0-108

896 0-1670

5

232

171 0-378

>5712 1350->5400

6

52

95 0-342

3088 792-9506

7

37

108 18-198

81 54-126

8

24

108 18-198

612 324-882

9

86

108 18-198

95 54-198

10

28

36 18-90

612 216-1670

11

30

125 54-272

320 255-378

12

11

5 0-18

108 54-126

13

290

5 0-18

164 54-504

14A

446

5 0-18

45 18-108

14B

323

5 0-18

23 0-54

14C

107

5 0-18

140 72-252

14D

84

5 0-18

86 36-126

15

56

50 18-90

25 0-72

16

14 0-36

63 0-234

17

188

18 0-72

>2927 54->5706

18

75

108 36-180

178 0-396

19

64

9 0-36

>2768 36->5400

20

100+

2601* 2110-3146*

>4403 1188->5400

21

240

27 0-36

>5400 >5400->5400

22

236

42 0-108

171 90-270

23

84

14 0-54

477 432-540

24

168

477 162-972

>5400 >5400->5400

* - This outside level appears to be contaminated with inside mold

> -Greater than

Twenty-one of the MGO's sampled had Penicillium spore levels that exceeded 5 times the outdoor levels in either the average spore levels, the range, or both. In some cases, the difference was over 100 times the outside level. These results suggest that the mold species most commonly associated with MGO's in Colorado are Penicillum sp. This is not a surprise since other investigations that we have conducted in Colorado have also involved Penicillium sp. In several of these prior investigations, the elevated concentrations of Penicillum mold spores were associated with hypersensitivity pneumonitis among workers in the contaminated areas. Levels of Aspergillus spores were only found to be elevated in one MGO (MGO#5).

Non-Viable Mold Levels

Non-viable mold spore measurements have the advantage over viable spore levels in that the spores do not have to be grown. Since not all mold spores that are captured using the Anderson Cascade Impactor are able to grow due to viability issues, the non-viable spore levels are usually higher than the viable mold levels. Since most of the health effects due

to mold exposure are caused by the allergens in the spores, the spores need not be viable to cause health effects.

Table #3 provides the results from of the total spore counts.

Table #3

Grow Plant #

Total Outside

Grow Rooms

average range

average range

1A

117 241

241

711 711

1B

77 241

241

1960 1960

1C

58 241

241

1410 1410

1D

28 241

241

2

160 NA NA

2860 2860 1380 1380-7610

3

65 509 274-744

645 505-745

4

670 221 161-281

958 345-2090

5

232 556 295-816

18020 1960-45700

6

52 1470 1370-1570

3345 2670-4020

7

37 989 928-1050

900 780-1020

8

24 989 928-1050

534 471-597

9

86 989 928-1050

489 465-512

10

28 7430 6690-8170

1893 653-2880

11

30 3670 3370-3970

279 189-369

12

11 6075 5960-6190

13

290 2695 2240-3150

783 716-850 304 0-654

14A

446 503 498-507

464 464

14B

323 503 498-507

179 84-274

14C

107 503 498-507

14D

84 503 498-507

334 323-344 157 139-175

15

56 1067 864-1270

102 70-140

16

274 273-274

1045 0-2520

17

188 787 681-893

18

75 439 168-710

11196 893-25200 863 365-1490

19

64 751 231-1270

48454 245-134000

20 100+

1840 1350-2330

6868 5130-9820

21

240 186 126-246

P

P

22

236 13850 11100-16600

2500 2010-2990

23

84 95 77-112

2988 766-5210

24

168 2380 1770-2990

10800 10100-11500

P = Particle overload on spore trap.

These results are similar to Table #1 and indicate that a number of the MGO's had spore levels that were elevated above the background level. The biggest difference between the two tables are the results for MGO#14 where the viable levels of spores were much higher than the number of counted spores. The reason for this discrepancy is unknown at this time.

Table #4 shows the non-viable spore counts for the Penicillium/Aspergillus species only:

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download